Updated query classes to align to interface for common aligned
operations.
Extracted repeated string-identifier-based finding from page/chapter
repos to shared higher-level entity queries.
For book, shelves and chapters.
Made much of the existing handling generic to entity types.
Added new MixedEntityListLoader to help load lists somewhat efficiently.
Only manually tested so far.
- Adapted existing page picker to be usable elsewhere.
- Added endpoint for getting templates for entity picker.
- Added search template filter to support above.
- Updated book save handling to check/validate submitted template.
- Allows non-visible pages to flow through the save process, if not
being changed.
- Updated page deletes to handle removal of default usage on books.
- Tweaked wording and form styles to suit.
- Updated migration to explicity reflect default value.
Swapped back handling to instead be pre-determined instead of being
based upon session/referrer which would cause inconsistent results when
referrer data was not available (redirect to app-loaded images/files).
To support, this adds a mechansism to provide a URL through request
data.
Also cleaned up some imports in code while making changes.
Closes#4656.
Ensures some sensible text is always in webhook text data.
Also aligned some notification reporting to use centralised activity
system instead of custom success events.
For #4216
